Ok so I followed the Android Tutorials at the developer.android.com to build my first app. So to create a simple user interface I added a button and text field given in the tutorial. But when I run it on my phone, I don't see the buttons or text field.
package com.example.lookforbuttons;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView tv= new TextView(this);
tv.setText("Buttons");
setContentView(tv);
}
}
The .xml file where I describe the layout is this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<EditText android:id="#+id/edit_message"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="#string/edit_message" />
<Button android:id="#+id/send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send" />
</LinearLayout>
and the strings.xml looks like this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">Buttons</string>
<string name="edit_message">Enter a message</string>
<string name="button_send">Send</string>
<string name="action_settings">Settings</string>
<string name="title_activity_main">MainActivity</string>
</resources>
The target android version is 4.03 since I am testing it on 4.03 phone. When I run this I only "Buttons" printed and no button or text field. Thanks.
You call setContentView twice. When you do this, the second time is what you will see on the screen because it will overwrite whatever layout you called in the first call to setContentView(). So since you call
setContentView(tv);
last you only have the TextView. Remove that line and you should see your EditText and your Button.
In your code you are setting setContentview() twice. That means you are changing the layout which contains Button and TextView with second setContentview().
If you want to dynamically add new TextView to your layout. Remove the second setContentView() and assign an id to your LinearLayout in xml. Then find it in your Java code and say linearlayout.add(textview)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/lv"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<EditText android:id="#+id/edittext"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="#string/edit_message" />
<Button android:id="#+id/send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send" />
</LinearLayout>
Linearlayout lv=(Linearlayout) findViewById(R.id.lv);
lv.add(textview);
Related
Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 2 years ago.
Improve this question
I build an android app with the help of an tutorial.
This is the MainActivity.java:-
package com.example.listdisplay;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainActivity extends Activity {
// Array of strings...
String[] mobileArray = {"Android","IPhone","WindowsMobile","Blackberry",
"WebOS","Ubuntu","Windows7","Max OS X", "PHP", "Java", "HTML", "CSS", "JavaScript","MySQL"};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayAdapter adapter = new ArrayAdapter<String>(this,
R.layout.activity_listview, mobileArray);
ListView listView = (ListView) findViewById(R.id.mobile_list);
listView.setAdapter(adapter);
}
}
This is the activity_main.xml:-
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ListView
android:id="#+id/mobile_list"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
This is the activity_listview.xml:-
<?xml version="1.0" encoding="utf-8"?>
<!-- Single List Item Design -->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/label"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="20dip"
android:textSize="16dip"
android:textStyle="bold"
android:orientation="horizontal">
</TextView>
When I change the textview to any other view like cardview and more things. The app is going to crashed.
I want to do more styling with cardview and layout. Like i also tried with the linearlayout.I inserted this textview with an button in linear layout. But, it is still going to crash.
Please help me.
You can't change the TextView from activity_listview.xml because ArrayAdapterconstructor expects a Layout with an only EditText.
If you want to modify that, you have to implement a custom ArrayAdaptermaking a class that extends from it.
You can follow next Medium tutorial to achieve this.
https://medium.com/mindorks/custom-array-adapters-made-easy-b6c4930560dd
If you want to add a Button or something else, you need the custom ArrayAdapter.
If you want to do more styling with card view so you don't need change text view to card view just simply write your code like below code...
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
app:cardCornerRadius="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/label"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dip"
android:textSize="16dip"
android:textStyle="bold"
android:orientation="horizontal">
</TextView>
</LinearLayout>
</androidx.cardview.widget.CardView>
Create your custom xml file:
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="8dp">
<TextView
android:id="#+id/label"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="This is just text" />
</LinearLayout>
</androidx.cardview.widget.CardView>
Important part is android:id="#+id/label" in TextView.
And add the R.id.label to third parameter of ArrayAdapter, like that:
ArrayAdapter adapter = new ArrayAdapter<String>(this,
R.layout.activity_listview, R.id.label, mobileArray);
So I have an xml that consists of a linear layout containing a Button and a TextView like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="100dp"
android:orientation="vertical">
<Button
android:id="#+id/btnCell"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="start"
android:paddingLeft="40dp"
android:text="Button"
android:textColor="#color/blueText" />
<View
android:height="wrap_content"
android:width="wrap_content"
android:background="#drawable/Test"/>
</LinearLayout>
And I want to use this same layout inside other layouts in a different xml. I need the same button at every time, so I reuse it by including it in the two layouts (both layouts are in the same xml, but ones is hidden):
First one
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/image"
/>
<include layout="#layout/buttonLayout"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
Second One:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:visibility="gone"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/image"
/>
<include layout="#layout/buttonLayout"/>
<CheckBox
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
So I show the first layout and hide the second one at the beginning of the app , as the user moves within the interface, the layouts exchange so that the other one is shown and the first one hidden.
The thing is that I declare the Button in my java activity class like this:
btnCell = (Button) thirdView.findViewById(R.id.btnCell);
btnCell.setOnClickListener(this);
And implemented the listener.
#Override
public void onClick(View v) {
if (v == btnCell) {
System.out.println("entered if");
}
System.out.println("entered function");
}
The problem is that when I click the button when the first view is shown and the second hidden, the button works just fine, but when I unhide the second layout, hide the first one, and proceed to click the button, that should be the same as the first one but in a different layout, nothing happens. I searched and find out, that this happens because the id is assigned only to the button shown in the first layout because of view hierarchy, but not the one in the second layout. How can I make both buttons react to the same action, without declaring a new button in each layout but instead reusing it?
I have used this type of layout. you can create Id different for both and inflate that view and give different name so You can differentiate both thing.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/image"
/>
<include android:id="+id/firstOne" layout="#layout/buttonLayout"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
android second one is
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:visibility="gone"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/image"
/>
<include android:id="+id/secondTwo" layout="#layout/buttonLayout"/>
<CheckBox
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
The Problem is both the layout are include in same layout file and the id of that
button are same so whenever you click on any of the button at the same time event will fire on both button like both are clicked.
So, you have to give the different id for both the button I hope it works fine..
You can add a different Id for each included layout:
<include android:id="+id/layout_a" layout="#layout/buttonLayout"/>
and
<include android:id="+id/layout_b" layout="#layout/buttonLayout"/>
and then use two findViewById to reach them:
btnCellA = (Button)thirdView.findViewById(R.id.layout_a).findViewById(R.id.btnCell);
btnCellB = (Button)thirdView.findViewById(R.id.layout_b).findViewById(R.id.btnCell);
Here i have to create a one button in which i want to write string as well as create a icon .
I used the font-awesome and font-tello but in both of them i facing a problem in out put the the icon is converted into a number format any one give solution.
Thank You in advance..
MainActivity.java
Typeface newFont = null;
Button cameraBtn = null;
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
cameraBtn = (Button)findViewById(R.id.button1);
newButton = Typeface.createFromAsset(getAssets(), "fonts/fonta.ttf");
cameraBtn.setTypeface(newButton);
cameraBtn.setText(R.string.icon);
}
string.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">TestApplication</string>
<string name="action_settings">Settings</string>
<string name="action_search">Search</string>
<string name="icon"></string>
</resources>
Activity_Main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity"
android:background="#151415" >
<Button
android:id="#+id/button3"
android:layout_width="120dp"
android:layout_height="75dp"
android:layout_weight="0.335"
android:background="#666666"
android:text="Button" />
</LinearLayout>
Also i putted the font-awesm.ttf into assets/fonts ..
Output
"2131099652 Text"
I got solution
camerabtn.append("TEXT HERE");
Thank You All Of you for Solutions..
I have a list that is intended to be below toggle buttons. The list grabs data from a server and then parses them. My XML is as follows:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<ToggleButton
android:id="#+id/toggle_button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:textOff="Apps"
android:textOn="Apps" />
<ToggleButton
android:id="#+id/toggle_button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/toggle_button1"
android:layout_weight="1"
android:textOff="VMs"
android:textOn="VMs" />
<ToggleButton
android:id="#+id/toggle_button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/toggle_button2"
android:layout_weight="1"
android:textOff="Groups"
android:textOn="Groups" />
<ListView
android:id="#+id/mylist"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/toggle_button1" />
</RelativeLayout>
Code for the actual fragment:
public class ProblemFragment extends SherlockListFragment
{
private SeparatedListAdapter list;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.getSherlockActivity().setContentView(R.layout.problem_layout);
list = new SeparatedListAdapter(this.getSherlockActivity(), new Layout(R.layout.separated_list_adapter_two_text, R.id.two_text_title, R.id.two_text_desc));
ToggleButton b1 = (ToggleButton) this.getSherlockActivity().findViewById(R.id.toggle_button1);
ToggleButton b2 = (ToggleButton) this.getSherlockActivity().findViewById(R.id.toggle_button2);
ToggleButton b3 = (ToggleButton) this.getSherlockActivity().findViewById(R.id.toggle_button3);
setListAdapter(list);
refresh();
}
public void refresh()
{
list = new SeparatedListAdapter(this.getSherlockActivity(), new Layout(R.layout.separated_list_adapter_two_text, R.id.two_text_title, R.id.two_text_desc));
refreshStats();
}
public void refreshStats()
{
//Omitted parsing code
list.addSection(new String("Hello world!!"));
setListAdapter(list);
}
}
However, when I use setListAdapter(list), the buttons are overwritten. They are visible before the app retrieves the data and parses it, but they are overwritten after I call setListAdapter. How can i fix this?
First, remove
android:orientation="horizontal"
from your root layout. RelativeLayout doesn't have an orientation property. Also, weight is for child elements of a LinearLayout and when you use it then you should assign the width of each child view to 0dp for horizontal orientation and height="0dp" for vertical orientation.
Then wrap your ToggleButtons in a LinearLayout, vertical or horizontal orientation, and give it the property
android:layout_alignParentTop="true"
then give your ListView the property
android:layout_below="#id/idOfLinearLayout"
So it may look something like
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:id="#+id/toggleLL"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true">
<ToggleButton
android:id="#+id/toggle_button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOff="Apps"
android:textOn="Apps" />
<ToggleButton
android:id="#+id/toggle_button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOff="VMs"
android:textOn="VMs" />
<ToggleButton
android:id="#+id/toggle_button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOff="Groups"
android:textOn="Groups" />
</LinearLayout>
<ListView
android:id="#+id/mylist"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/toggleLL" />
</RelativeLayout>
I also removed the RelativeLayout properties from the ToggleButtons since they are now wrapped in a LinearLayout. And you had a circular view error there with assigning the second ToggleButton to the right of itself which may have been a copy/paste error. Hope this helps.
Note that the default orientation for a LinearLayout is horizontal so leaving that property out will give you that effect.
Oh! I can not test your XML but I think that you need scrollbars! If the list is filled with a lot of entries, it can became bigger that the screen, making the buttons disappear because they are pushed up by the list. Try to add a scroll to the whole layout.
Something like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<ScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<!-- Original layout here -->
</ScrollView>
</LinearLayout>
Of course, if you just put only one layout inside the scrollview, there is no need for the outer layout:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Original layout here -->
</ScrollView>
Hello there people of stack overflow, I have just started developing with android and have run into a bit of a problem. I am trying to run a very simple app that has a single button, which when clicked updates the text to the current time. However, the app does not even start up. I am following a book. "Beginning Android 2", and am just learning about XML layouts. The same app worked without an XML layout, so it may be something to do with my xml.
Anyways, I'm running it on a droid 2, if that helps.
Heres the codes.
package apt.tutorial;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import java.util.Date;
public class FirstApp extends Activity implements View.OnClickListener {
/** Called when the activity is first created. */
Button btn;
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
btn = (Button)findViewById(R.id.button);
btn.setOnClickListener(this);
updateTime();
}
public void onClick(View view) {
updateTime();
}
private void updateTime() {
btn.setText(new Date().toString());
}
}
And the XML file
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/button"
android:text=""
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
Thanks in advance.
You should enclose the button inside a layout (linear, relative, etc):
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" >
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/button"
android:text=""
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</LinearLayout>
Both answers are incorrect. The only line missing in that xml is the first one:
<?xml version="1.0" encoding="utf-8"?>
Of course you will need some kind of ViewGroup to make any meaningful UI, but setContentView can take any View as parameter
The problem is that your root layout must be a ViewGroup. Change the layout to something like this for example:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:id="#+id/button"
android:text=""
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</LinearLayout>